Shaper write fails for integer values

[Aliaksei-Tatarynchyk]

yaml file:

test.properties:
  prop: 12345

Error is

18:07:14       [exec] Traceback (most recent call last):
18:07:14       [exec]   File "/usr/local/bin/shaper", line 10, in <module>
18:07:14       [exec]     sys.exit(main())
18:07:14       [exec]   File "/usr/local/lib/python2.7/site-packages/shaper/cli.py", line 161, in main
18:07:14       [exec]     manager.write_properties(datastructure, arguments.out)
18:07:14       [exec]   File "/usr/local/lib/python2.7/site-packages/shaper/manager.py", line 53, in write_properties
18:07:14       [exec]     os.path.join(directories, property_file),
18:07:14       [exec]   File "/usr/local/lib/python2.7/site-packages/shaper/libs/parser.py", line 102, in write
18:07:14       [exec]     parser_class().write(data, path)
18:07:14       [exec]   File "/usr/local/lib/python2.7/site-packages/shaper/libs/parser.py", line 316, in write
18:07:14       [exec]     '{}={}'.format(item[0], self._process_multiline_string(item[1])) for item in data.items()
18:07:14       [exec]   File "/usr/local/lib/python2.7/site-packages/shaper/libs/parser.py", line 316, in <genexpr>
18:07:14       [exec]     '{}={}'.format(item[0], self._process_multiline_string(item[1])) for item in data.items()
18:07:14       [exec]   File "/usr/local/lib/python2.7/site-packages/shaper/libs/parser.py", line 269, in _process_multiline_string
18:07:14       [exec]     string_splitted = string.splitlines()
18:07:14       [exec] AttributeError: 'int' object has no attribute 'splitlines'